Introduction to the Ilímaussaq intrusion with a summary of the reported investigations

Abstract

The Ilimaussaq intrusion belongs to the late Precambrian Gardar province of South Greenland (fig. 1). The province ean be regarded as a cratogenic rift province with similarities to the East African rift system and the Oslo igneous provinee (Upton, 1974; Emeleus & Upton, 1976). The provinee consists of continental sandstones, and a variety of volcanic and plutonic igneous rocks many of which are alkaline. An important series of faults have influenced the position of the plutonic centres and presumably facilitated the rise of magma into the upper erust. The alkaline roeks evolved towards Si-rich melts such as comendites and alkali granites, and towards Si-poar melts such as phonolites and nepheline syenites. Both types of evolution are present at Ilimaussaq (fig. 2).